This invention relates to the field of deburring of articles, and provides an improved and automated system for performing the deburring operation.
It has long been known that articles of many shapes and sizes can be deburred by placing them in a barrel, or other container, and by spinning the barrel. Preferably, an abrasive medium is added to the barrel, and the centrifugal force acting between the articles and the medium, and the walls of the container, remove the burrs or "flashing" on the articles. One example of this general method is shown in U.S. Pat. No. 3,013,365.
It has also been known that the deburring process is made more efficient when the container is rotated in two directions at once. That is, the container is rotated around its own axis, and the table on which the container is mounted also rotates, but in the opposite direction. The effect of these rotations is a more thoroughly deburred product. Examples of this kind of centrifugal deburring are shown in U.S. Pat. Nos. 3,503,157 and 4,308,693.
The table which holds the barrel of articles to be deburred typically rotates at about 100 rotations per minute (rpm), and the container rotates about its own axis at about 25 rpm. In many cases, the articles will be deburred after about 20-30 minutes of rotation. The amount of time required to debur the articles depends upon the nature of the articles. This time period can sometimes be as short as about 10 minutes, or as long as several hours.
In the prior art, the table and the barrel are geared, or otherwise linked, such that the ratio of the speed of rotation of the barrel to that of the table is constant.
A major constraint in the operation of centrifugal deburring systems of the prior art is the time required to move the articles into and out of the system. In the systems of the prior art, the barrels cannot be removed from the rotating table. Instead, the articles to be deburred are poured into the barrels as they sit on the table. The barrels have bottoms which can open, to allow the finished products to leave the machine. The barrels must remain stopped while both barrels are being unloaded.
Moreover, the process of reloading the barrels is very time consuming. First, the articles to be deburred, as well as one or two kinds of abrasive media, must be separately delivered to the barrels. Then a measured quantity of water, which can be up to 50 gallons, is poured into the barrels. These operations take time, especially when two or more barrels must be filled. Clearly, the system cannot rotate during the filling. During loading and unloading, the deburring system is, in effect, disabled. Thus, in the prior art, the overall speed of the system has depended critically on the efficiency of the loading and unloading.
The present invention avoids the problem discussed above by providing a centrifugal deburring apparatus having removable barrels. The device of the present invention includes a latch mechanism with which a barrel can be attached to the table, and which permits the barrel to be easily removed from the table when deburring is complete. The contents of the barrel can be quickly removed and processed elsewhere, while another barrel of articles can be placed on the table for centrifugal deburring. The present invention therefore achieves substantial savings of time in the deburring of articles, and can process far more articles, in a given time, than all known systems of the prior art.
The present invention also has the advantage that it is automated. The system operates under the control of a computer, which guides all of the moving parts. While a given barrel is being rotated on the table, the contents of another barrel can be dumped into a collector, and still another barrel can be filled with new articles to be deburred. Moreover, the system can operate with more than one rotating table. The timing of the system is chosen such that one table is rotating while the barrels on the other table are being loaded or unloaded. This automatic operation adds to the efficiency of the system, in contrast with the devices of the prior art.
The present invention also provides a much greater choice of speeds of rotation, as compared with systems of the prior art. The barrel and the table can be rotated at any selected speeds, because they are driven by independent motors.